Belt-type calculator with transfer mechanism

ABSTRACT

A belt-type adding machine has a transfer mechanism using teeth along the edge of a belt and a pawl on the adjacent belt for engaging a tooth on every tenth step and moving the belt one tooth space. The pawl moves into position on the ninth step. If it rests there, the teeth are free to move past it if necessary, due to resilient mounting of the pawl.

United States Patent [56] Reierences Cited UNITED STATES PATENTS 1,657 923 1/1928 Goshko...H................... 2,732,130

[72] inventor Harry A. Pburgess 41 Coleman Ave. i i/mt, Chntitnm, NJ. 07928 [21] AppLNo. 883,572 [22] Filed 1/1956 Rosenberg...r..............

Dec.9,1969 [45] Patented Aug.10,1971

Primary Examiner-Stephen J. Tomsky Attorney-Blair, St. Onge and Mayers [S4] BELT-TYPE CALCULATOR WRTH TRANSFER MECHANISM 10 Claims, 9 Drawing Figs.

ABSTRACT: A belt-type adding machine has a transfer hanism using teeth aiong the edge of a belt and a pawl on GUM 15/26, the adjacent belt for engaging a tooth on every tenth step and moving the be1t one tooth space. The pawl moves into position on the ninth step if it rests there, the teeth are free to move past it if necessary, due to resilient mounting of the pawl.

c e m new m m .1 I81- M 7 y 1 3 5 CH4 3 6S 2 nu W n m m .m m m d e m U h F .1 .1. 1. 2 .l 0 5 5 U.

BELT-TYPE CALCULATOR WITH TRANSFER MECHANISM The present invention relates to mechanical calculators, specifically to an adding machine of simplified construction which can be of small dimensions such that it can be held in the hand when using, and yet is fully automatic in operation, requiring a minimum of attention by the user.

Adding machines are known in which endless belts or tapes or chains are mounted side by side, one per digital order (units, ls, etc.) and are independently movable lengthwise a distance proportional to a number to be indicated. 0n the th step of such movement it is necessary to move the next higher order belt one step to effect a "carry" in adding or a borrow in subtracting.

The invention provides an automatic transfer mechanism for causing such movement of the adjacent tape when necessary, without any attention on the part of the user.

The principal object of the invention is a transfer mechanism of the general type indicated which will be of simple and straightforward construction and which will be reliable in operation under all conditions of normal use.

Other and ancilary objects and features of the invention will be made clear as the description proceeds.

In the drawings,

FIG. I shows the face of a five-column adder according to the invention, with the cover plate partly broken away to show internal construction details;

FIG. 2 is a side view of one of the structural sections of the calculator of FIG. I as viewed from the right;

FIG. 3 is a sectional view of FIG. 2 taken at the line 3 3;

FIGS. 4 and 5 are enlarged views of details of the transfer mechanism shown in FIG. I;

FIG. 6 is a fragmentary view in diagram to assist in describing how the machine of FIG. I may be adapted to subtracting as well as adding;

FIGS. 7 and 8 are detail views of an alternative transfer mechanism; and I FIG. 9 is a diagram to be referred to in describing the problem of lost motion.

Referring to FIG. I, the enclosing case has sides ll, 12, a plain backplate I3 and a front or cover plate 14. Inside the case are sections of similar construction, one of which is shown at 15, FIGS. 2 and 3, which are held in place by bolts 16, I6 passing through holes 17, I7 and sides 11 of the casing.

As shown in FIGS. 2 and 3, the section 15 is built up on a channel plate 18 as a base, having a flange 20 running entirely around the base, which includes a straight portion and semicircular end portions, as shown. Mounted on the longitudinal axis of baseplate iii are the block 2! and the pulleys or sheaves 22. the latter being freely rotatable on axial pins 23. These sheaves are undercut at the bottom as is also the block 21 (FIG. 3) so as to form with the flange 20 an endless trsclt or channel 24 running around the periphery of the section at its base.

At a suitable point along this channel a slot is provided in plate Itl, as at 25, and the two strips as along the sides of this slot are depressed into arcunte form, providing a gate" the purpose of which will be described.

In FIG. 3 the full line portion represents the end section at the extreme right in FIG. I. When extended to include the upper part shown dotted in FIG. 3, the Figure represents any of the intermediate sections of FIG. ii. The section at the en: trcmc left in FIG. 1 is similar to that at the extreme right we cept that it need have no gate (25, 26).

Turning now to the assembly of the structural s ctions in FIG. I, each section has an endless belt or tape 2%"! passing around the rollers 22 so as to be easily andsnioothly movable lengthwise of the belt l.e., in its longitudinal direction. Par forations 28 are provided at uniform steps and these lie directlyunderneeth a slot in the front cover plate in the case of each belt as shown at 30,250 in FlGat". by inserting estylus into one of these perforations the tape may be moved downward in the Figure a desired number of steps. The block 21 has a longitudinal slot 33 underneath the perforations to allow the point of the stylus to project into it.

The tapes have numerals disposed in decades in line with windows 32 in the cover plate so asto be visible one at a time depending on the position of the belt. In the present description it is assumed that each belt has three decades or a total of 30 characters.

These windows 32, which constitute the register, and the shots 30 are positioned in panels of the cover plate that are depressed slightly so as to lie just above the belts to permit greater accuracy in reading. The higher or plateau portions between the depressed portions are to accommodate the channels (18,20) of the sections, which are wider than the blocks 21. The bottom end of each slot 30 is in line with the foot of slot 33, so that when the stylus is perpendicular to the front plate and at its extreme lowest point it is in contact with the ends of both slots, thus providing an accurate stop point. The bottom surface of channel 33 has a hump 35 near its lower end over which the point of the stylus rides just before reaching its stop. This assists the user in securing accuracy since he senses the slight rise as the stylus goes over the hump and immediately comes against the stop.

Each of the belts except that at the extreme right in FIG. 1 is equipped with teeth as along its right side evenly spaced apart by one number unit or interval. Each belt except that on the extreme left in FIG. I is equipped with a pawl 37 adapted to engage a tooth on the adjacent hclt when in a certain position.

These elements are clearly shown in FIGS. 4 and 5. The teeth 36 are in line with the slot 25 and move freely through this slot whenever the belt is advanced. When at the end of its movement the belt always has one of its teeth in position to be engaged by pawl 37 if the pawl happens to he in the gate, which term is here used to mean the part of the channel com prising slot 2.5 and arcuate strips 26,26 (see FIG. 3).

The pawl is integral with a shank 38 which projects into a tubular bearing 39 so as to be freely rotatable, and this hearing member is fixedly secured to the belt 27. The shoulder to of the pawl is made of spring steel or the like and urges the pawl tothe left in H6. 4 so as to bear against the strips 2s. When belt 27 moves downward in the Figure the end of the pawl is forced by the cam action of the strips 26 toward the right,

where further downward movement causes it to bear against the straight part of the base plate 18. Space is provided to ac commodate the pawl in the dotted line position, FIG. i, by cutting a recess in the belt 257.

There are three pawls in each section spaced equidistant from one another along the belt as indicated in FIG. 2. The free end of each pawl is slightly narrower than the width of the channel so as to permit the pawl to pass easily along the chau neland around the sheaves where they are undercut. The bearing 3b, 39 of each pawl facilitates travel around the sheave.

The operation will now be described. To condition the ma hine for performing addition, the belts are advanced by use of a stylus to line up a complete row of zeros in the rcgllllfil, in the case illustrated in FIG. i. that is, there will be five acres. The first number to be added is entered into the register in similar manner, the order being immaterial as to whether from left to right or otherwise. in the Figure the number 27,39! has been so entered. If the neat number to be added is, for erarnple, 325, the stylus is placed in the hole opposite 3 in the middle column and is pulled downward against the stop This adds to the number in the middle window giving 6 as the sum. in similar manner the 2 is entered, changing the 9 to l and at. the same time changing the 6 of the middle column to 7 by action of the transfer mechanism. The 5 is then entered in the right hand register column, giving a s. The sum is there fore 27,? l 6.

in this single example, the two types of action by the transfer mechanism are illustrated. When the first digit 3 (of the number 325) was entered, three teeth of the center belt moved past the pawl 37, each tooth pushing the pawl back out of its way against the spring tension in the pawl. As soon as a tooth passes the end of the pawl, the latter snaps back over the top of the tooth into the position shown in FIGS. l and 4. There is but little friction between the sloping edge of a tooth and the pawl as compared with the frictional resistance against movement of the belt on which the pawl is mounted, so that the belt remains in its position.

The second type of action is the downward propulsion of the middle belt by the pawl in contact with a tooth in the gate- (FIGS. 1 and 4). Although the belt carrying the pawl has moved two steps or intervals, it causes the adjacent belt to move exactly one interval and no more, since it becomes uncoupled from the tooth as the tooth reaches the lower end of the gate, by the cam action of curved strips 26,26. Thus, the transfer mechanism comprises means for transferring longitudinal movement from a lower order to the next higher order belt, and it also includes provision, in the resilient mounting for the pawl, for preventing transfer of advance longitudinal movement from the higher order to the lower order belt.

In order to subtract as well as add each belt is provided with two rows of numerals (FIG. 6), one in ascending and the other in descending order, instead of the single column of the previous Figures; and the register has a double window 32' corresponding to the two rows of numerals, in the case of each belt. The structure is otherwise the same as in the other Figures and the operation is the same. It will be understood that the purpose of FIG. 6 is to show the relation of the parts for easy understanding and that the previous Figures should be referred to for structural details, FIG. 6 being in the nature of a diagram.

When subtracting, only the right-hand half of the register window pair is used, and it will be convenient to provide a cover which can be slid over the other half (indicated by shading in the Figure). These covers would be ganged for convenience of operation.

To illustrate the operation in subtracting, suppose the two columns of the register shown carry the number 50. if the number ii is to be subtracted, each of the two belts is pulled downward one step by use of a stylus, it being assumed that the column on the left is the tens column. In the left column this movement replaces by 4 in the register, and in the right= hand column it replaces the zero by 9. Also pawl 37 moves the 10s belt another step to bring up 3 in the register, the result being 39.

If the two belts are assumed to be restored to the position shown in the Figure and the Add" windows are used, the number in the register is 49, and addition can be performed as already described in connection with FIG. 1.

By using the construction of FIG. 1 but replacing the backplate by one similar to the front cover but inverted, the machine can be used exclusively on its front side for adding, and on its rear side for subtracting. in turning it over, the top edge is brought forward half a complete turn, thus turning it upside down. The belts may then be moved downward by the stylus in performing subtraction, exactly as previously described for performing addition. instead of the double win= dow 32 for the register, each side would have a series of single windows, each in line with the row of numerals involved in the function assigned to that side.

Reference will now be made to FIGS. 7 and d which show an alternative type of gate and pawl construction. Here the springis omitted from the pawl and is made part ofthe gets. it is therefore used in common by all three pawls.

The pawl 37 has the same shank portion 38 as that shown in FIG. 4 and is attached to the belt in the some way. A cap 33 is secured to the shank 38 and prevents it from pulling out of the tubular bearing 39. Instead of the spring 40 there is only a pivot 41 which allows the free end of the pawl 37' to follow the curved strips 26,26 through the gate. During the rest of its journey along the endless track 24 (FIGS. 2 and 3) the two degrees of motion permitted by the bearing 38,39 and pivot ll of the track. The top wall of the'track shown in FIG. 3 consists of the upper edge of the undercut made in block 21. In the construction shown in FIGS. 7. and 8 this is duplicated on the opposite edge of the track by a-turned-over strip 42 at the rim of the flange 20. A gap is left between strip 42 and block 21 to allow free passage of pawl 37' and shank 38 along the track asshown in FIG. 8.

The pawl 37' as shown in FIG. 8 is an inverted T, the crossbar 44 of which lies athwart the track and reaches nearly from side to side. The spring referred to is shown at 45 in FIG. 7 and a duplicate is provided at 45 on the opposite side (FIG. 8). FIG. 8 assumes that part of the block 21 is brokenaway to permit viewing the pawl and springs by looking to the left in FIG. 7. These two springs are secured to the upper wall of the track in any suitable manner and their free ends press against the crossbar oi the pawl. Two slabs 46,46 are attached to the op posite sides of the track and are of such a thickness as to leave between them a gap the same as that existing between strip 42 and block 2i. The edges ofthese slabs facing gate strips 26 are curved to match the curve of the strips. The upper ends of the slabs 46,46 as shown in FIG. 7 are sloped slightly to conform to the arcuate path of travel of the pawl when it is forced to the right in FIG. 7 by an advancing tooth against the tension of the free end of the spring 45. The free end of the spring projects into a groove 47 in slab 46 which serves as a guide. This groove ends just short of the left-hand edge of the slab to limit movement of spring 45 to the left.

The operation of the construction shown in FIGS. '7 and 8 will be clear from the foregoing description. When a pawl in its travel along the track reaches the gate, the springs 45,45 cause the crossbar 44 to be deflected into the gate and to he brought into contact with the curved strips 26,26. As the free ends of the springs are reached, the curved pathis continued by the slabs 46,46 in conjunction with strips 26,26 throughout the rest of the gate and into the straight portion of the track.

In case the belt to which the pawl is attached is advanced only to the point where the pawl comes to rest against a tooth in the gate, then as in the case of FIG. 4 construction, the ad= jacent belt can be advanced independently without causing advance of the pawl or the belt to which it is attached. The sloping edges ofthe teeth displace the pawl out of the way, al= lowing the teeth to bypass the pawl. After slight initial displacement, the crossbar d4 of the pawl passes above the and of slab do as shown in FIG. 7 and any advancement (downward travel) of the pawl or its belt is prevented. The part of the spring ifithat is in contact with the crossbar 44 is shown in FIG. 7 as having a V=crimp which together with a ribon the surface of the bar, exerts a small stcadying force against ad vance of the pawl in its initial displacement. This restraining force is too small to interfere with intentional advance of the pawl by actuation of its belt by the stylus as previously described.

It will be noted that the construction shown in FIGS. 7 and ti allows the pawls to traverse all of the track except that in the gate without rubbing against the walls undcr spring tension and, therefore, with less friction than in the case of the FIG. a construction.

instead of an inverted T as a form for the pawl, it could use an L=shape, in which case the outermost spring as and slab so could be omitted. An advantage would be that the track could be narrower, allowing the overall thickness of the machine (FlG. l) to be no greater than with the FIG. a construction, or perhaps less.

Referring again to FIGS. s and 7, it is desirable that the pawl whsn at rest in the gate should be in contact with a tooth so that upon the initial downward movement of the pawl the adjacent belt also begins its movement and the belt then complctcs a full step of advance. However, this contact must be somewhat loose so as to insure that the pawl will move on top of the nest tooth that enters the gate when moved by the allow the pawl to travel freely, being guided by the four walls stylus until the stop is reached.

The small amount of play that must be allowed will not be I significant except possibly in those cases in which a solid row of nines (in adding) exists in the register over several columns and a number is then entered in the lowest order column, in which case all of the nines to the left must be changed to zero in the register. Even in this situation the accumulated lost motion may be unobjectionable until it is great enough to cause ambiguity in the register reading or in identifying the number of the hole 28 into which the stylus is to be inserted.

This difficulty can be compensated by the simple expedient of progressively shortening (very slightly) the belts of ascending order as indicated in the diagram of FIG. 9. The belt on the right is a low-order belt such as unity order. That on the left is a high-order belt, and it is assumed that several belts intervene in ascending order from right to left. The pawls 37 of all of the belts are assumed to be in their respective gates in contact with a tooth.

lf now the unity belt be moved one step to enter a l, motion is transmitted to all of the belts by the transfer mechanisms. Let it be supposed, however, that due to the lost motion above discussed, the lowest order belt moves the distance d before any motion is transmitted to the highest order belt, as shown by the diagram. if the tooth spacing of the highest order belt is made equal to h as indicated, this belt will complete a full step by the time the lowest order belt reaches the end of one step of its travel. The ambiguity difficulty is thus avoided. A similar diagram can be drawn for each of the intermediate order belts and a determination be made as to the amount a belt should be shortened. Depending upon the limit of tolerance, only a few of the higher order belts may need to be shortened in practice.

in the case of a shortened belt, the upper sheave or bearing needs no change, but the lower bearing shaft is replaced by a stub shaft supported on the section base 18 and extending through only one sheave. The perforations 28 will be spaced in proportion to the belt length as well as the tooth space and the spacing of the numerals.

The belts may consist of any material having suitable flexibility and toughness, either in a single piece or fabricated from a number of elements linked together, interlaced, or otherwise fashioned into an endless belt. I have used experimentally mo tion picture film base for the belts.

The terms step, unit space and interval obviously mean the distance a belt moves in advancing from one number to the next, which is also the same as a tooth space.

The teeth can vary widely in shape so long as they are capable of carrying out the function described. They need not be formed as integral parts of the belt but can be of a different material and otherwise disposed.

Obviously, the capacity of the calculator can beincreased by adding other structural sections similar to those illustrated.

,Other variations are permissible within the scope and spirit of the claims.

What i claim is:

l. in a calculator of the type in which endless belts carrying number information are mounted side by side in ascending digital order from belt to belt for independent longitudinal movement, transfer mechanism comprising a series of equally spaced teeth constrained to be moved in exact correspondence with the movement of a higher order one of said belts, a pawl carried by the adjacent lower order belt in proximity to said teeth, gate means for permitting engagement of said pawl with said teeth only when adjacent thereto and spring means urging said pawl into engagement with a said tooth to allow the pawl to advance said first belt one tooth space.

2. in a calculator according to claim 1, said teeth being constructed, when in motion relative to said pawl, to move said pawl out of engagement with a tooth against the tension of said spring means.

3. in a calculator according to claim 1, said teeth being distributed along one edge of said higher order belt and united thereto.

4. in a calculator according to claim 1, means operating in conjunction with said pawl for preventingasubstantial advance movement of the ad acent lower order sit by independent movement of said higher order belt.

5. in a calculator according to claim 1, said teeth shaped to move said pawl against the tension of said spring means by cam action during independent movement of said higher order belt, and a stop member situated to bar advancement of said adjacent lower order belt by said pawl when so moved by said teeth.

6. in a calculator according to claim I, partitions separating said respective belts from one another, each partition including a gate within which one of said teeth is in position to be engaged by said pawl.

7. in a calculator according to claim 1, partitions separating said respective belts from one another, each partition including a gate having a curved wall throughout its length and a longitudinai slot therein adapted to receive said teeth, and means to deflect said pawl toward said curved wall to engage a tooth in said slot.

8. in a calculator according to claim l, a shield between respective belts, having a gate therein, said shield isolating said pawl from said teeth throughout its travel except when it is in said gate, said pawl when in said gate engaging one of said teeth.

9. in a calculator according to claim 1. said belts of higher order being progressively varied in length by an amount such as to compensate for the accumulated lost motion in the operation of the transfer mechanism.

10. in a calculator according to claim 1, a front face for said calculator having a register for displaying numerals carried by said belts and involved in addition, and a rear face having a re gister for displaying other numerals carried by said belts and involved in subtraction. 

1. In a calculator of the type in which endless belts carrying number information are mounted side by side in ascending digital order from belt to belt for independent longitudinal movement, transfer mechanism comprising a series of equally spaced teeth constrained to be moved in exact correspondence with the movement of a higher order one of said belts, a pawl carried by the adjacent lower order belt in proximity to said teeth, gate means for permitting engagement of said pawl with said teeth only when adjacent thereto and spring means urging said pawl into engagement with a said tooth to allow the pawl to advance said first belt one tooth space.
 2. In a calculator according to claim 1, said teeth being constructed, when in motion relative to said pawl, to move said pawl out of engagement with a tooth against the tension of said spring means.
 3. In a calculator according to claim 1, said teeth being distributed along one edge of said higher order belt and united thereto.
 4. In a calculator according to claim 1, means operating in conjunction with said pawl for preventing substantial advance movement of the adjacent lower order belt by independent movement of said higher order belt.
 5. In a calculator according to claim 1, said teeth shaped to move said pawl against the tension of said spring means by cam action during independent movement of said higher order belt, and a stop member situated to bar advancement of said adjacent lower order belt by said pawl when so moved by said teeth.
 6. In a calculator according to claim 1, partitions separating said respective belts from one another, each partition including a gate within which one of said teeth is in position to be engaged by said pawl.
 7. In a calculator according to claim 1, partitions separating said respective belts from one another, each partition including a gate having a curved wall throughout its length and a longitudinal slot therein adapted to receive said teeth, and means to deflect said pawl toward said curved wall to engage a tooth in said slot.
 8. In a calculator according to claim 1, a shield between respective belts, having a gate therein, said shield isolating said pawl from said teeth throughout its travel except when it is in said gate, said pawl when in said gate engaging one of said teeth.
 9. In a calculator according to claim 1, said belts of higher order being progressively varied in length by an amount such as to compensate for the accumulated lost motion in the operation of the transfer mechanism.
 10. In a calculator according to claim 1, a front face for said calculator having a register for displaying numerals carried by said belts and involved in addition, and a rear face having a register for displaying other numerals carried by said belts and involved in subtraction. 